Object carriers and lighted tags for an object control and tracking system

ABSTRACT

Object carriers are provided for use with an object tracking and control system of the type having a storage receptacle with a tray provided with an array of slots for receiving ID tags bearing touch memory devices. A computer-based controller is provided for detecting the absence or presence and identity of ID tags disposed in the slots. The carrier of this invention includes a container with an openable panel for placing objects in and removing objects from the carrier. A thin plastic tongue projects from the carrier and bears a touch memory device. Carriers bearing objects to be tracked are placed in the storage receptacle with their tongues extending into the slots of the receptacle. The controller can thus detect and log the removal and replacement of the carrier in the storage receptacle. In one embodiment, the opening and closing of the carrier when it is not stored in the receptacle is detected and logged for tracking access to the carrier in more detail. The invention also includes lighted key tags for use with an object tracking system. Lighted key tags stored in an object tracking system are adapted to emit light when their attached keys are requested by a user. A portion of the key tag may be formed of transparent material that forms a light guide through which the light is transmitted.

REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of co-pending U.S. patent applicationSer. No. 10/005,235 filed on Dec. 5, 2001, which is a continuation ofU.S. patent application Ser. No. 09/792,987 filed Feb. 26, 2001, nowU.S. Pat. No. 6,501,379, which is a continuation of U.S. patentapplication Ser. No. 09/393,225 filed Sep. 9, 1999, now U.S. Pat. No.6,195,005, which, in turn, claims the benefit of the filing date of U.S.provisional patent application Ser. No. 60/099,954 filed Sep. 11, 1998.

TECHNICAL FIELD

This invention relates generally to object tracking and control systemsand more particularly to enhancements usable with such systems fortracking larger or collections of keys and loose objects other thankeys.

BACKGROUND OF THE INVENTION

Many objects have intrinsic value or have value because they provideaccess to other valuable objects. For instance, jewelry and coins haveinherent and intrinsic value while keys, such as keys to vehicles, havevalue because they provide access to other valuable objects, namelyautomobiles and trucks. Further, access to and control of some items,such as narcotics for example, needs to be monitored, tracked, andcontrolled to assure against unauthorized access or to assure thatproper and appropriate access is catalogued. There is a serious need tobe able to track, catalogue access to, and control such objects in a waythat is reliable, simple to implement, and virtually tamper proof.

In the past, a variety of systems have been implemented to track andcontrol objects. In the case of keys in an automobile dealership, forexample, peg boards have been used to keep track of the keys assalespersons, maintenance personnel, and others remove keys for accessto vehicles. Generally, sign-out sheets have been used to log thecheck-in and check-out of such keys. Obviously, such a manual system oftracking has numerous shortcomings due in large part to the very realpotential of human error and forgetfulness in carrying out the sign-inand sign-out procedures.

More recently, automated computer controlled key tracking systems havebeen implemented for tracking, for example, vehicle keys at car lots andkeys to the apartments of apartment complexes. One such systemparticularly applicable to the present invention is the key trackingsystem disclosed and claimed in my U.S. Pat. Nos. 5,801,628; 6,075,441;6,317,044; 6,204,764; and 6,407,665, the disclosures of which are herebyincorporated fully by reference. In this system, referred to herein asthe “Key Track” system, keys to a vehicle are attached with a rivet orthe like to a thin plastic key tag having a depending tongue. The tonguecarries a small button-shaped electronic touch memory device, whichstores a ID code. The tongues of the key tags are configured to beinsertable in an array of slots formed in a panel within a storagedrawer. A printed circuit back plane is disposed beneath the array ofslots and is provided with a plurality of pairs of metal contacts, eachpair of contacts being aligned with a corresponding one of the slots.When the tongue of a key tag is inserted in a selected one of the slots,its touch memory device is engaged by the corresponding pair ofcontacts.

A computer based controller is electronically coupled through a datamatrix to the contacts on the back plane and periodically polls eachpair of contacts, preferably several times per second, to determine thepresence or absence of a touch memory device and thus which slotscontain key tags and which do not. When a slot contains a key tag, thetouch memory device of the tag is read to determine its ID code, fromwhich the identity of the particular key on the tag can be determinedthrough a table lookup. In this way, the absence or presence andlocation of the key tags and their associated keys can be noted by thecontroller each time the array of contacts are polled. If a tag presentin a slot on a prior polling is absent on a subsequent polling, then thecontroller notes that that the tag and its key has been removed from thestorage drawer. Conversely, if a key tag is detected in a previouslyempty slot, the controller notes that the tag and its key have beenreplaced in the storage drawer. The removal and replacement of keys istherefore continuously monitored.

An access feature requires an authorized user such a salesperson toenter an ID code to unlock and access the storage drawer. When thehistory of removal and replacement of key tags and their keys iscombined with other information, such as the time at which tags areremoved and replaced and the identities of the persons who accessed thedrawer and times of access, access to the keys in the drawer can becontrolled and a detailed tracking log can be created. This systemgreatly decreases instances of lost keys, reduces the time required tofind checked-out keys, and generally provides automatic tracking andcontrol of the keys, and thus, to a large extent, controls and tracksthe vehicles to which they provide access.

While the Key Track system described above has proven extremely valuablein the tracking and control of keys, it nevertheless has been limitedsomewhat in the situations to which it is readily applicable. Forexample, the tags used with the system are made of thin relatively flatplastic material that generally provides for the attachment of a singleor only a few keys to the tag. It has been difficult to attach a largecollection of keys such as keys on a key ring and even more difficult toattach larger special function keys such as keys that incorporateelectronic transmitters for locking and unlocking a car remotely. Inthese situations, it has been experienced that keys can fall or hanginto the slots of the Key Track drawer and short out one or more of thecontacts on the backplane, resulting in system errors or failure. Whilesimply providing larger tags is helpful, it has not proven to be acomplete solution. Furthermore, the system has generally been poorlyapplicable to the tracking of loose items such as, for example, jewelry,narcotics, and the like because such items cannot easily be attached toa tag. The present invention is intended to enhance and expand the basicKey Track system for application to these and other situations.

Another relative shortcoming of present electronic key tracking systemssuch as the Key Track system, and object tracking systems in general,has been limitations resulting from the fact that the keys are onlydetectable upon check-in and check-out at a central storage location.This has meant that tracking of keys has generally been limited tokeeping a log of when the keys are physically removed and replaced in acentral storage receptacle. The disposition of keys in the interim hasnot been trackable. Nevertheless, it is clearly useful to track themovement and use of keys and other objects in the interim between thetimes when they are checked out and checked back in at the centralstorage location. For example, in the case of tracking use of keys toapartments by maintenance personnel, it is desirable to know not onlythat a group of keys were checked out and checked back in at particulartimes, but also when the keys were used in the interim to accessapartments. such information can be useful, for example, when claims oftheft or vandalism are levied against security personnel. It can also beuseful in general security dispatching to insure that security guardscheck in at all required stations while making security rounds and tolog the activities of such guards during their rounds. In the trackingof narcotics at a hospital, it is desirable to know when and by whomparticular narcotics are checked out and checked back in and also thetime at which the narcotics are accessed in the interim betweencheck-out and check-in times. In this way, confirmation that patientsreceive the proper prescriptions at the proper times can easily be madeby referring to the resulting log of check-out, access, and check intimes. The basic Key Track system has not been readily applicable tosuch situations. Further, in prior Key Track systems, when a key isrequested by a user, the computer controller identifies the location ofthe key in the Key Track drawer by displaying the row and column of thekey. Thus user must then locate this row and column to check out thekey. In some cases, users consider this system of identifying andlocating a requested key to be inconvenient and cumbersome and it can besubject to human error.

Thus, even though the Key Track system has proven very useful, thereexists a continuing need to enhance the system by, among other things,providing for the tracking of larger and bulkier keys and keycollections, by providing for the tracking and control of the use ofkeys and other articles in the interim between check out and check in,and, in a more general sense, to provide for the tracking and control oflarger or loose items such as jewelry and narcotics. A further needexists for a convenient and more robust method of identifying arequested key or other object to a user so that the user can quicklylocate the object for check-out. It is to the provision of suchenhancements and improvements that the present invention is primarilydirected.

SUMMARY OF THE INVENTION

Briefly described, the present invention, in one preferred embodimentthereof, comprises enhancements to the Key Track system disclosed in myabove referenced and incorporated U.S. patents in order to adapt thesystem for use in tracking and controlling large collections of or bulkykeys, such as keys on a key ring or remote access transmitter keys, andin tracking and controlling larger or loose objects other than keys. Theinvention further comprises improved methods, devices, and circuits foridentifying a requested key or other object to a user visually byactivating a light on a tag or box associated with the requested object.

The heart of the first enhancement is a carrier or box adapted tocontain a ring of keys, a larger electronic access key, or objects otherthan keys, such as, for example, jewelry or narcotics. In oneembodiment, the carrier comprises a rectangular box-shaped containerwith an openable door panel on one side. The door panel may be hingedfor access to the container or may be displacably or removably attachedin another way such as by sliding attachment slots. In one configurationfor use with keys on a key ring, the container has a slot on its bottomside and the key ring is provided with an ID tag having a relativelythin plastic tongue carrying a touch memory device. In use, thecontainer is opened and the key ring is placed in the container with itsID tag extending through the slot in the bottom of the container. Thecontainer is then shut to contain the key ring and its keys whereuponthe entire container can be selectively placed in and removed from theKey Track drawer with the protruding ID tag extending into one of thekey tag slots in the drawer. The key ring is thus tracked and access toit controlled in the same manner as a single key attached to atraditional key tag.

To facilitate the alignment of containers with slots in the Key Trackdrawer, an overlay formed of stamped metal or a wire grid can beattached within the Key Track drawer overlying the slots. The overlaydefines an array of openings, each sized to receive a container. Theopenings are positioned such that when a container is slid into one ofthe openings, the protruding ID tag is directed into one of the slots inthe drawer allowing the controller to read the presence of the ID tagand its key ring within the drawer.

Another embodiment of the invention is intended for use with bulky keyshaving built in remote entry transmitters or with remote entrytransmitters not combined with keys. It has previously been difficult toattach such items to a key tag in the traditional key track system. Asmaller container, preferably made of molded plastic, is sized tocontain a remote entry key or transmitter. The container comprisesrectangular box having an open side for access. A tongue, similar to thetongues on the key tags of the Key Track system, is fixed to the bottomwall of the container and depends therefrom. A touch memory device iscarried by the tongue and the tongue is configured to be inserted intothe slots in the Key Track drawer. A sliding panel is adapted to slideonto the container from the bottom side thereof and to cover the openside for closing the container and capturing a key in the container.When a key is closed in the container, the container can be placed inone of the slots in a Key Track drawer with its tongue and touch memorydevice extending into the slot in the traditional way. The attachedcontroller is thus able to detect and track the insertion and subsequentremoval of the container from the drawer. Since the sliding panel isslid onto the box from the bottom to close the container, the panelcannot be removed for access to the key without first removing thecontainer from the Key Track drawer, which will be detected by thecontroller. Thus, since the keys cannot be removed without detection, ameasure of security for relatively expensive remote entry transmittersand keys is provided. In addition, since the key is closed within thecontainer, it is protected and its identity cannot be determined simplyby looking into the Key Track drawer. Only the controller is able toidentify the location of a particular key within the drawer upon aproper query by an authorized user.

In yet another embodiment of the invention, the carrier and Key Tracksystem are enhanced to expand the system beyond its traditional use fortracking keys to a general object tracking and control system. Thisembodiment is particularly useful for tracking valuable objects such asjewelry or for tracking the use of controlled substances such asnarcotics and medication. A set of containers is provided, eachcontainer having a box with an open side and a hinged panel that coversthe open side and closes the container. The container is provided with aslot or pocket in which a printed circuit board can be slid. The printedcircuit board carries a memory device storing a ID code and may alsocarry other components such as a microcontroller, ancillary memory, anRF transmitter, an RFID tag, and related components. Conductive pads onthe printed circuit board are coupled to the components on the board forelectronically accessing the components.

A drawer or other storage receptacle is provided for receiving thecontainers of this embodiment. The drawer has an overlay panel formedwith an array of openings or bays each sized to receive one of thecontainers. A printed circuit back plane is disposed behind the overlaypanel and has a plurality of sets of conductive contacts, each set ofcontacts positioned to engage the conductive pads of a container'sprinted circuit board when the container is inserted into thecorresponding bay. The contacts are wired in a data matrix, which isconnected to a computer-based controller as in the traditional Key Tracksystem. Use of this embodiment is similar to use of the traditional KeyTrack system. The controller detects and logs the removal andreplacement of containers in the drawer by reading the ID codes of thememory devices associated with the containers.

This embodiment also may include a further enhancement wherein theprinted circuit boards in the containers are more sophisticated and areconfigured to log the opening and closing of the container between thetimes when it is checked out and checked back in at the storage drawer.The container may also be provided with sensors to gather otherinformation in the interim period such as, for example, the times whenthe container passed location transmitters, identification numbers frompatient arm bands or ID buttons, or other information. This informationcan be downloaded to the controller upon check in and correlated withother information to provide valuable data compilations and reports.Such information is useful, for example, in the dispensing of drugs topatients in a hospital, where it is desired to log when the drugs arechecked out, by whom, at what times the container was opened whilechecked out for access to the drugs stored inside, and the identities ofpatients provided with drugs. This information can be correlated tomedication schedules for patients to insure that patients are beingprovided with the proper drugs at the proper times.

The printed circuit boards of this embodiment can be even furtherenhanced with simple RF transmitters and/or RFID tags available from avariety of manufacturers. RFID tags are adapted to transmit a codeand/or other information to a receiver coupled to the computer-basedcontroller and can be used as an alternative to touch memory devices.Other RF transmitters can be provided if desired to transmit a code uponthe occurrence of prescribed events such as, for example, each time thedoor of the container is opened and its contents accessed. Suchfunctionality provides for real time tracking of access to the containerin the interim between check-out and check-in times.

In another embodiment of the invention, an object container or a key tagis provided with an LED that, when lit, projects a light that is visibleto a user when observing all the tags and containers within a Key Trakdrawer. Circuitry within the container or tag is adapted to activate theLED when a user requests a key or other trackable object attached to atag or contained within a container. In one embodiment, the entire upperportion of a key tag is made of a transparent material and the LEDdirects its light into the bottom of this material. In this way, theedges of the upper portion of the key tag appears to light up when a keyattached to the tag is requested by a user. Thus, the user can easilyidentify the location of and remove a requested key simply by lookinginto a crowded Key Track drawer and noting the carrier or tag that islighted. Preferably, a delay function is incorporated into the tag sothat the LED remains on for a few seconds after the tag is removed fromits slot.

Thus, an improved and enhanced method and system for tracking andcontrolling keys and other objects is now provided. The traditional KeyTrack system is enhanced to accommodate large numbers of keys on a keyring, bulky or unusually shaped keys and remote entry transmitters, andvaluable or controlled loose objects other than keys. In one embodiment,object containers are provided with active electronics, which tracks andlogs access to the container between the times when it is check out andchecked back in. In another embodiment, an RF transmitter or RFID tag isprovided for radio frequency communication to the controller. Furtherenhancements include lighting a tag or container associated with arequested object to identify it visually to a requesting user. These andother features, objects, and advantages of the invention will becomemore apparent upon review of the detailed description set forth belowtaken in conjunction with the accompanying drawing figures, which arebriefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a closable carrier usable with the KeyTrack system to store and track large numbers of keys on a key ring.

FIG. 2 illustrates the carrier of FIG. 1 inserted in one of the slots ofa tray of the Key Track system.

FIG. 3A illustrates a guide or overlay usable with the Key Track systemand carrier of FIG. 1 to align and secure the carrier, prevent itsopening while mounted in the tray, and to partition the slots of thetray to receive multiple carriers.

FIG. 3B illustrates another embodiment of the container guide in theform of a wire grid defining slots for receiving and aligning carriers.

FIG. 4 is a perspective exploded view of an alternate embodiment of thecarrier for use with the Key Track system when it is desired to trackunusually shaped or sized keys, such as keys incorporating remote entrytransmitters.

FIG. 5 is a perspective partially cut-away view of an embodiment of theinvention in the form of an object tracking system for tracking objectssuch as jewelry or narcotics.

FIG. 6 is a perspective partially exploded view of the carrier of theembodiment of FIG. 5 illustrating the removable printed circuit boardthereof.

FIG. 7 is a functional electronic schematic diagram showing a preferredcircuit for use with the embodiment of FIG. 5.

FIG. 8 is an exploded view illustrating the mounting of a touch memorydevice in a conducting rather than a non conducting tag.

FIG. 9 is a perspective partially exploded view of a lighted key tagthat embodies principles of the invention in one preferred embodiment.

FIG. 10 is a perspective partially exploded view of a lighted key tagthat embodies principles of the invention in an alternate form.

FIG. 11 is a front plan view of the lighted key tag of FIG. 10illustrating the appearance of the tag when assembled.

FIG. 12 is an electronic schematic diagram showing an alternateembodiment of a circuit suitable for use in the lighted key tags andlighted containers of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now in more detail to the drawings, in which like numeralsrefer to like parts throughout the several views, FIG. 1 illustrates acarrier for ringed keys that embodies principles of the invention in onepreferred form. The carrier 11 comprises a generally rectangularbox-shaped body 12 formed by a top panel 13, a bottom panel 14, a leftside panel 16, a right side panel 17, and a back panel 18. A front panel19 preferably is hinged along one side to the edge of the right sidepanel 17 (or, alternatively to the left or any other side panel) toprovide a selectively closable hinged door on the carrier. Locking tabs30 and 35 preferably are provided on the door and box. The locking tabshave holes that align with one another when the hinged door is closed. Alock or tamper evident ring can be inserted through the aligned holes.In this way, the carrier can be locked shut if desired so that onlyauthorized personnel may access its contents. Alternatively, a tamperevident ring that, when cut, indicates that the carrier has beenaccessed may be provided. Finally, the carrier preferably is providedwith an appropriate latch 10, which may be any suitable form of latch,for releasably latching the door shut when closed to hold the key ringsecurely in place.

The bottom panel 14 is provided with a slot 21 that extends from thefront edge of the bottom panel to a position inwardly spaced from thefront edge. A lateral partition 23 spans the left and right side panelsand a pair of guide walls 20 extend between the partition 23 and thebottom panel 14 straddling the location of the slot 21 to define a guideslot 22 between the guide walls 20.

An ID tag 24 is adapted to be received in the guide slot 22 andcomprises a head 26 from which a relatively thin tongue 27 depends. Thehead 26 is sized and shaped to slide, as indicated by arrows 25, intoand fit partially within the guide 22 with its tongue 27 projectingdownwardly through the slot 21. The tongue 27 may be formed of plasticif desired but also may be formed of a more durable and tamper resistantmaterial such as stainless steel or aluminum. A tongue of stainlesssteel or aluminum renders the ID tag much less susceptible to tamperingor defeat by cutting the ID tag and absconding with the keys, althoughit requires electrically isolated mounting of the touch memory device asdescribed in more detail below. The location of the ID tag in the slotas described also serves to locate the key ring and the keys attachedthereto in the upper portion of the carrier. In this way, the keys areisolated from the tag, are held in place in an organized fashion, and donot interfere with operation of the touch memory device.

The head 26 of the ID tag is adapted to be mounted on a key ring with agroup of keys 31 (only a few of which are shown in FIG. 1 for clarity)and includes a hole for this purpose. A touch memory device, such asDS1990A touch memory device available from Dallas Semiconductor, isattached to and carried by the tongue 27 in a manner similar to that inwhich touch memory devices are carried by the key tags in the standardKey Track system. If the tongue 27 is made of plastic or otherelectrically insulating material, the touch memory device, which has aradially projecting rim at one end, is simply pressed through anappropriately sized hole in the tongue and secured with a mounting ring.In the event the tongue is made of steel, aluminum, or anotherconducting material, it may be necessary first to install an insulatingspacer and then the touch memory device to insulate the touch memorydevice from the conductive mounting material of the tongue (see FIG. 8).In either case, the touch memory device is carried by the tongue asshown.

In use, the key ring 29 and keys 31 are placed in the carrier 11 asindicated by arrows 25 with the head 26 of the ID tag 24 being insertedinto the guide 22 such that its tongue 27 projects downwardly from thecontainer 12 through the slot 21. When so inserted, the keys and keyring reside in the upper portion of the carrier above the location ofthe partition 23 and the tongue 27 with its touch memory device projectsdownwardly from the bottom panel 14 through the slot 21. The front panel19 can then be hinged shut to enclose and contain the keys and keep themfrom flopping about. The front panel can be releasably latched shut withlatch 10 if desired and a lock or tamper evident ring can be installedin the locking tabs 30 and 35 for enhanced security.

When the front panel 19 is closed, the carrier 11 with keys inside formsa rectangular box as illustrated in FIG. 2 with the tongue 27 of the IDtag projecting downwardly from the bottom panel 14 of the box. Thecarrier can then be inserted into a Key Track tray 32 with the tongue ofthe ID tag extending into one of the slots 33 of the tray to engage thetouch memory device with the pair of electrical contacts correspondingto the slot. The ID code stored in the touch memory device can then beread by the attached computer-based controller to determine the presenceand location in the tray of the keys associated with the ID tag and todetermine when the carrier and its keys are removed. The process,structure, and electronics for reading the touch memory device isdescribed in detail in my U.S. Pat. No. 5,801,628 and also disclosed inthe manufacturer's specifications and thus need not be described indetail here.

It will be noted from FIG. 2 that, when the carrier of the illustratedembodiment is inserted in a selected slot of the key track storage tray32, the carrier covers the two slots of the tray on either side of theslot in which its ID tag extends, rendering these slots unavailable foruse by other key tags or carriers. While the carrier is shown to covertwo slots in FIG. 2, it will be understood that less or more slots mightbe covered and rendered inaccessible depending upon the size of thecarrier. This does not represent a particular disadvantage, however,since the controller will simply read that the covered slots areunoccupied and key tags inserted in other available slots will still bedetected and identified when they are present. Although a Key Trackdrawer will accommodate fewer carriers than traditional key tags, theadvantage of tracking and controlling large numbers of keys on key ringsin the same way that single keys on key tags are tracked far outweighsthe disadvantage of any reduced capacity of the drawer. As detailedbelow, custom overlays or custom trays may also be used to accommodatethe carriers if desired. Further, additional drawers can be added to thesystem as need to accommodate larger numbers of key tags and carriersand any mix of object carriers and key tags can be used with theexisting drawer configuration of the Key Track system.

FIG. 3A illustrates an enhancement of the carrier system of FIGS. 1 and2. Here, an overlay or guide 36 is provided for covering a row of slots33 in the Key Track tray and providing a positioning guide for aplurality of carriers 11. The guide 36, which can be formed of punchedand bent sheet metal, comprises opposed sides 37 and opposed ends 38(only one end is visible in FIG. 3) that form a generally rectangularbox shaped structure. A flange 39 is provided at the bottom of each end38 and holes 41 are bored in the flange for attaching and securing theguide 36 to the Key Track tray 32. The top 40 of the guide 36 is formedto define at least one socket or receptacle 42 that is sized to receivethe carrier 11 therein. Preferably, the receptacle 42 is provided withguide flanges 43 projecting downwardly therefrom to guide the carrier 11into the receptacle when it is inserted therein as indicated by arrows46.

Additional receptacles 44 are also provided in the guide 36 extendingtherealong and defining an array of carrier receptacles. The guide 36thus functions to provide an array of receptacles for receiving carriers11 with each socket properly aligning its respective carrier with aselected slot 33 in the Key Track tray. In addition, the receptacleshold the hinged front panels 19 of the carriers shut when they are inposition within the receptacles. This is important because it prevents athief from opening the receptacle without first removing it from thetray, which will be detected by the controller. If an unauthorizedremoval is detected by the controller, appropriate alarms can begenerated and actions taken to alert security personnel. Thus, an extrameasure of security is provided by the overlay.

FIG. 3B illustrates an alternate embodiment of a carrier guide oroverlay for attachment to a Key Track tray to partition the tray intoreceptacles for receiving carriers. In this embodiment, the tray 32 of akey track drawer is shown with an array of slots 33 for receivingtongues of key tags bearing touch memory devices. A carrier 11, aspreviously described, is formed of a box 16 and a closable hinged door19. A tongue 27 depends from the carrier and bears a touch memory device28. a wire frame guide 141 is formed with spaced apart elongated rails142 bridged by a set of spaced apart connecting segments 144. The rails142 and connecting segments 144 define an array of rectangularreceptacles, each sized to receive a carrier 11, as indicated by thearrows in FIG. 3B.

Vertically depending legs 146 project downwardly from the rails 142 and143 and are anchored to the key track tray with appropriate fastenerssuch as shoulders and bolts. The legs 146 secure the wire frame guide tothe key track tray and properly position the rectangular receptacles sothat when a carrier 11 is inserted into one of the receptacles, thetongue 27 thereof is directed into one of the slots 33. Thus, the wireframe guide performs a function similar to that of the guide of FIG. 3A,but with a less expensive wire frame structure. Further, since the wireframe is more open than a bent metal guide, the slots 33 can be usedwith traditional key tags when not holding a carrier and much bettervisibility is provided for visually identifying the objects in the tray.A simple two row guide is shown in FIG. 3B. It should be understood,however, that multiple row guides are possible and within the scope ofthe invention. Indeed, the entire key track panel could be overlaid witha wire grid allowing insertion of carriers and/or key tags in anycombination. Further, the us of guides such as those illustrated inFIGS. 3A and 3B allows the carriers of this invention to be used withvertically oriented panels and backplanes that may be, for example,mounted on a wall. More efficient storage configurations are thereforepossible.

FIG. 4 illustrates another carrier for use with the Key Track system.This carrier is designed to allow odd shaped, bulky, or expensive keysto be tracked with the key track system in the same way as a loose keyattached to an ID tag. These types of keys include keys, such as key 71,with large heads that incorporate transmitters for remotely locking andunlocking the doors of a vehicle to which they correspond. Remote doorlock transmitters not incorporated into the vehicle key can also betracked as well as other small items. The carrier 56 comprises a case57, which can be made of molded plastic or other appropriate material.The case 57 is formed by a right side panel 58, a left side panel 59, atop panel 61, a bottom panel 62, and a back panel 63, which, in thepreferred embodiment, are unitarily molded of plastic. The side panels58 and 59 are formed with respective grooves or races 64 and 66 thatextend along the outside top edges thereof. The grooves 64 and 66 areshaped and sized for slidably receiving a sliding cover 67 havingdepending sides or skirts 68 on three sides thereof. Inwardly opposedribs (not visible in FIG. 4) are formed on the inside portions of theside skirts 68 and are sized and positioned to slide into the grooves 64and 66 when the sliding cover 67 is moved onto the case 57 as indicatedby arrows 69. In this way, the case can be closed with a key or otheritem inside by sliding the cover onto the case.

An ID tab 72 is provided with a touch memory or other ID device 73 andis secured at one end to the bottom panel 62 of the case 57. The ID tabis sized and configured to be inserted into a selected slot of a KeyTrack tray. In use, a key 71 is placed in the carrier and closed thereinby sliding the sliding cover 67 into place. Preferably, the key issecured to the box with a loop of cabling or other appropriate tether(not shown) to prevent the box from becoming separated from its key. Thecarrier is then stored on the Key Track tray by inserting its ID tabinto a selected slot of the tray. The Key Track controller can thentrack and control access to the key within the carrier in the usual way.Preferably, the carrier 57 is sized to take up no more than one space onthe Key Track tray so that other key tags or carriers can be insertedinto adjacent slots of the tray.

The carriers of FIGS. 1 through 4 have been described in terms of thestorage and tracking of keys. It will be clear to those of ordinaryskill in the art, however, that a wide variety of items can be stored inthe carriers and thus tracked by the key track controller. For example,use of these carriers might convert a car key tracking system into asystem for tracking jewelry, narcotics, or other small valuable ordangerous items. An added advantage when tracking such items is that theitems are concealed and hidden within their carriers. Accordingly, onlythe Key Track controller is able to inform an authorized user of thelocation within the drawer of each item. An unauthorized user or wouldbe thief cannot simply look into a drawer full of carriers and locateany particular item. Other uses for the carriers of this invention mightbe conceived by those of skill in the art such that, clearly, thepresent invention is not intended to be limited just to the storage andtracking of keys.

FIGS. 5 and 6 illustrate an object tracking and control system thatembodies principles of the present inventions in yet another form. Theobject tracking system illustrated in these figures can be used tostore, monitor, and track a wide variety of items from automotive keysand apartment keys to narcotics and jewelry, to important files orpapers. The system comprises a carrier 81 that, in the illustratedembodiment, is a rectangular box, for containing items to be tracked andcontrolled. The carrier 81 is sized to be received in a rectangularsocket 82 formed in the surface of a receptacle panel 83. The panel 83may be formed with a large array of receptacles for receiving andcontinuing a corresponding large number of carriers.

A back plane 84 is mounted behind or beneath the receptacle panel 83 andpreferably is spaced therefrom a distance substantially equal to theheight of the rectangular carrier 81. In this way, when the carrier isinserted into the receptacle 82 to the back plane, its top panel 86 issubstantially flush with the surface of the receptacle panel 83. Asdescribed in more detail below, this configuration inhibits a thief fromremoving the carrier from the receptacle panel by force.

It will be understood that while only one receptacle and one carrier isillustrated in FIG. 5 for clarity of description, a complete systempreferably would include a receptacle panel formed with an array of aplurality of receptacles for receiving a plurality of carriers.

In addition to its top panel 86, the carrier 81 is formed with a bottompanel 87, a left side panel 88, a right side panel 89, a back panel 91,and a hinged front panel 92 (FIG. 6). The back panel 91 in the preferredembodiment is formed with a slot or pocket 108 that extends from thebottom panel 87 to the top panel 86. The pocket 108 has an opening 96formed therein adjacent the bottom panel of the carrier. The pocket issized to receive and hold a relatively narrow printed circuit board 93with a portion of the bottom edge of the printed circuit board exposedthrough the opening 96 for purposes described in more detail below.

The lower left-hand corner of the carrier 81 is formed with a latch 99defined by a sloped strike 101 and an indentation 102. A solenoid andplunger assembly 103 is mounted to the back plane 84 at a positionadjacent the location of the latch 99 by means of an appropriatemounting bracket (omitted from FIG. 5 for clarity). The assembly 103includes a plunger 104 that is spring biased to its extended position(the spring assembly is not shown in FIG. 5 but spring biased solenoidassemblies are available commercially, are well known to those of skillin the art, and can be retracted by application of a control voltage tothe solenoid). The strike 101 formed on the carrier is positioned toengage and retract the spring biased plunger 104 of the solenoid 103when the carrier is inserted into the receptacle 82. When the carrier isfully inserted, the plunger 104 snaps into the indentation 102 to lockthe carrier in place within the receptacle. The carrier can be releasedwith an appropriate control signal from the controller to retract theplunger 104 from the indentation 102. Thus the strike and plunger forman electronically releasable lock that secures the carrier in place inits receptacle until an appropriate signal is provided by thecontroller. Similar locks can also be provided with the carrierembodiments of FIGS. 1 through 4 if desired.

A leaf spring or other spring 107 preferably is provided for exertingupward biasing force on a carrier locked in the receptacle. In this way,when the carrier is released by applying an appropriate control signalto the solenoid 103 to retract its plunger, the leaf spring causes thecarrier to “pop” up out of the receptacle so that it can be grasped forremoval.

As illustrated in FIG. 5 and perhaps best seen in FIG. 6, the circuitboard 93 within the pocket 108 is etched to expose a set of conductivepads 94 positioned to be exposed through the opening of the pocket 96when the circuit board is in place therein. A set of correspondingcontacts 97 (FIG. 5) are fixed to the back plane 84 and are positionedfor electrically contacting the conducting pads 94 when the carrier isinserted completely into the receptacle 82. The contacts 97 are coupledthrough a data matrix or other appropriate communications buss to aremote computer-based controller as described in my prior U.S. patentsfor connecting the electronic components of the circuit board to thecontroller.

Referring now to FIG. 6, the carrier 81 is illustrated with its hingedfront panel 92 (which may also be a sliding or other appropriate type ofpanel) open and with the circuit board 93 displaced from the pocket 108of the carrier. Arrows 112 indicate insertion of the circuit board 93into the pocket 108. Once a circuit board is inserted and locked intoplace within a carrier, it becomes associated with the carrier and thusassociated with articles stored in the carrier.

The circuit board 93 carries integrated circuit components forperforming the method of the invention. In one embodiment, for example,the circuit board 93 is provided with a touch memory chip such as thetouch memory devices provided on ID tags as discussed above. In thiscase, the chip preferably is surface mounted to the board to save spacerather than being housed in a metal case or button. However, the primaryfunction of the memory chip remains the same; that is, to store andtransmit its unique internal code when appropriately polled with apolling signal. The memory chip is electrically coupled to theconducting pads 94 at the bottom of the circuit board and the contacts97 on the back plane are configured and positioned to engage theconductive pads for receiving the ID code of the memory device andtransmit it through the data matrix to the controller for detecting theabsence or presence and location of the associated carrier within one ofthe receptacles.

Alternatively, the circuit board might be provided with moresophisticated electronics including a microcontroller or microprocessor118 and associated components including a crystal 121 and battery 119. Awide variety of configurations are possible and a simple circuit isdepicted in FIG. 6 for clarity. The microcontroller, which includesinternal memory, may be coupled to an integrated circuit RF transmitterthat can be actuated by the microcontroller. A reed switch 113 can becoupled to the front panel of the carrier for communicating a signal tothe microcontroller 118 whenever the front panel 92 of the carrier isopened or closed. A light emitting diode (LED) 98 is provided at the topof the circuit board 93 and projects through an opening 111 in the topof the carrier when the board is inserted into the pocket 108.Preferably, the microcontroller is programmed to light the LED wheneverthe carrier is selected by the system controller of the tracking system.In this way, a user can easily find a selected carrier by identifyingthe carrier to the controller, whereupon the controller lights the LEDof the selected carrier and releases it by actuating the appropriatesolenoid.

The embodiment of FIGS. 5 and 6 has many and varied applications. Forexample, the microcontroller 118 preferably is programmed such that,during the time the carrier is removed from its storage location, arecord is kept in the memory of the microcontroller of the times whenthe hinged front panel of the carrier is open or closed. When thecarrier is returned to its storage location, this stored data isdownloaded and becomes a record of the use of the carrier and itscontents between the times it was checked-out and checked back in.

Alternatively, the microcontroller can be programmed to activate the RFtransmitter at intermittent times while the carrier is checked out or toactivate the transmitter whenever the door of the carrier is opened orclosed. This information, when transmitted back to the main computerbased controller, can be tallied in real time as a means of tracking useof the contents of the carrier. These capabilities are useful in a widevariety of situations such as, for example, to track not only whenmedication was checked out to give to a patient, but the time at whichthe carrier was opened to administer the medication. Questions aboutmedication delivery can thus be readily answered. A wide variety ofother sensors and data gathering capabilities can be provided in such acarrier embodiment including, but not limited to, biometricsinformation, time and ambient temperature information, informationgathered through data ports, and information from various types of onboard switches. Further, with on board intelligence, enhancedsubstantially autonomous functionality is possible. For example, thecarrier may be provided with an internal lock that is activated onlywhen an authorized user has checked out or attempts to open the carrier.

Another use of the embodiment of FIGS. 5 and 6 is in tracking keys to anapartment complex. One carrier might, for example, house keys to anentire floor of apartments with each key coupled to the microcontrollerso that the microcontroller can detect when a specific key is removed. Adetailed record of when the key set was checked out and when eachspecific key was removed from the carrier is thus easily maintained foruse in verifying when personnel had access to particular apartments. Theuse of RF transmitters associated with objects expands the effectivenessof tracking systems greatly.

FIG. 7 is a functional schematic diagram of a circuit usable in theimplementation of the embodiment of FIGS. 5 and 6. The circuit comprisesan addressable switch in the form of an integrated circuit coupled tothe ground, data, and Vin pads of the circuit board. The switch can be aDS2407 or DS2405 addressable switch chip available from DallasSemiconductors, or any other appropriate integrated circuit chip ordiscrete components suitable for performing the method of the invention.All such chips and components are specifically incorporated herein byreference and are equivalent to the specific chips disclosed in thepreferred embodiments.

I/O 1 of the addressable switch 140 in the embodiment illustrated inFIG. 7 is coupled through an LED 141 and a current limiting resistor 142to supply voltage Vin, which, is one embodiment, is supplied from thebackplane through one of the contacts 94 (FIG. 6). In anotherembodiment, and as an alternative to supplying Vin from the backplane ofan object tracking system, a battery 143 can be provided on the circuitboard, in which case only two pads 94 (FIG. 6), one for a data line andone for a ground, are required.

In the circuit of FIG. 7, I/O 2 of the addressable switch 140 is coupledto an on board sensor, which may be a loop detector sensor to detectwhen an object is removed from the carrier, a reed switch to detectopening of the carrier, of another type of sensor depending on theintended use of the system. Other I/O ports may be provided on someversions of the addressable switch 14 o and these may be coupled toother switches or elements, such as locks, latches, etc., for detectingor activating such elements as desired. In use, data can be provided toor read from the addressable switch 141 through the backplane of anobject control system. In this way, the central controller of the systemis able to download information from the switch regarding eventsrecorded in the interim between check out and check in of the carrier,upload instructions to the carrier to, for example, turn on its LED,unlock its cover, or otherwise, by appropriately activating one or moreof the I/O ports.

FIG. 8 illustrates a preferred method of attaching or mounting a touchmemory device to a steel, aluminum, or other conducting plate material,which may be used instead of a plastic tongue for added security. Anopening is formed in the conductive mounting material 150 and theopening is sized for receiving an insulation spacer 152 through which atouch memory ID button is received. An insulating washer 153 is securedaround the touch memory button on the other side of the mountingmaterial and a crimp ring is secured around the touch memory button tosecure it firmly in place within the opening. In this way, touch memorybuttons can be mounted in metal tags for added security while remainingelectrically isolated from the tags, which is required for properoperation.

FIGS. 9-12 depict further embodiments of the identification of requestedtrackable objects with light as shown in FIGS. 5-7 and discussed aboverelative to those figures. Whereas in the embodiment of FIGS. 5-7, thisconcept was applied to a trackable object in the form of a container, inthe embodiments of FIGS. 9-12 it is applied to a key tag of the typeusable with a Key Track system such as those disclosed in my priorpatents, which are incorporated herein by reference.

FIG. 9 illustrates a lighted key tag that embodies principles of theinvention in one preferred form. The key tag 201 comprises a lowerportion 202, a mid portion 204 and an upper portion 203. The mid portion204 in this embodiment includes a protective housing formed by a firsthousing section 206 and a second housing section 207 (shown in explodedperspective in FIG. 9) that are joined together with adhesive orappropriate fasteners to complete the protective housing. The protectivehousing encloses and protects the upper section 209 of a printed circuitboard (PCB), the lower section 208 of which projects downwardly from theprotective housing to form the lower portion 202 of the key tag. Theupper section 209 of the PCB carries an electronic circuit 211,described in more detail below, which is made up of various electroniccomponents. The electronic circuit thus is also enclosed within andprotected by the housing of the mid section 204 when the two housingsections 206 and 207 are joined together.

The lower section 208 of the PCB, which defines the lower portion 202 ofthe key tag, carries electrically conductive pads 212 that areconfigured and positioned to couple with corresponding electricalcontacts of a Key Track system when the lower portion 202 of the key tagis inserted in a slot 210 of the system. In the preferred embodiment, aconductive pad is formed on each side of the lower portion (the pad onone side is hidden in FIG. 9) and one pad bulges or protrudes outwardlyso that the key tag is polarized to be inserted in only one orientationinto a polarized slot 210 of the Key Track system. The conductive padsare electrically coupled via traces 213 to the electronic circuit 211 tocouple the controller of the Key Track system to the electronic circuit.It will thus be seen that the lower portion 202 of the key tag 201 formsa downwardly depending tongue that corresponds to the downwardlydepending tongue of a standard key tag such as that disclosed in theincorporated patents. Thus, the lighted key tag of the present inventionis completely compatible with a Key Track system and can be intermixedwith standard key tags, key boxes, and other trackable objects asdesired.

The upper portion 203 of the key tag 201 is securely mounted within themid portion 204 of the tag and has a bottom edge that generally abutsthe top edge of the PCB within the mid portion. The upper portion 203extends upwardly from the mid portion 206 to a top edge that, in thisembodiment, is shaped with tapers to resemble the top edge of a standardkey tag. The upper portion 302 also has vertically extending side edgesthat merge with the top edge thereof. A key attachment hole 217 is boredthrough the upper portion 203 of the key tag adjacent the top edgethereof. The hole 217 is sized to receive a rivet 219 or otherappropriate fastener for securely fastening a key (or keys) 218 to thekey tag in the same way that a key is attached to a standard key tag ofa Key Track system. It will be understood in view of the forgoing andupon review of the incorporated patents that the key tag of FIG. 9 issomewhat similar in size and appearance to a standard plastic key tag ofa Key Track system and, in fact, is configured to be used by a user ofsuch a system just as a standard key tag would be used. However, the keytag of this invention provides distinct advantages over a standard keytag, as will become apparent from the continuing description below.

The upper portion 203 of the key tag of FIG. 9 is made of an opticallytransparent or at least partially transparent material such as a clearor colored plastic, Plexiglas, or other appropriate material. The upperportion 203 therefore forms a light pipe or light guide that is capable,as a result of the physics of total internal reflection, of directinglight along its length with very little loss of light through its sidefaces. In this regard, the light guide formed by the transparent upperportion 203 functions in a manner similar to a fiber optic cable, whichalso can conduct light for long distances with very little loss. Theelectronic circuit (detailed below) includes a light source in the formof an LED 216. The LED is activated and lighted by the electroniccircuit when the key tag 201 is stored in a Key Track system and isaddressed by the system in response to a user request for the particularkey 218 attached to the tag. The LED in the illustrated embodiment ismounted at the top of the upper section 209 of the PCB within the midsection of the tag. The LED is oriented or aimed such that, whenlighted, the LED projects its light into the bottom edge of the lightguide that is formed by the transparent material of the upper portion203. In the illustrated embodiment, a small notch is formed in thebottom edge of the light guide to accommodate the LED, but scores ofother configurations of the LED and bottom edge of the light guide arepossible so long as the light from the LED is aimed and projected intothe light guide.

It should be appreciated in view of the forgoing that when the LED 216is lighted upon a request by a user for the key 218, the light projectedfrom the LED into the light guide is carried or directed upwardly withinand spreads throughout the upper portion 203 of the key tag. When thislight reaches the vertical side edges and top edge of the light guide,it exits the light guide and is projected outwardly from the edges ofthe key tag as indicated by rays in FIG. 9. In fact and in practice, thelight emitted from the edges of the light guide is surprisinglybrilliant with the effect that the edges of the upper portion 203 of thekey tag become very noticeably bright red (or another color dependingupon the color of the LED) and the tag is rendered highly visible amonga plurality of unlit tags. The visibility of the selected tag can beenhanced even further if the LEDs are caused to flash when the key tagis addressed. As a result, from a Key Track system user's point of view,when a key stored in the Key Track system is requested by the userthrough the computer interface of the system, the lighted key tag 201 towhich the requested key is attached lights up to identify the requestedkey visually to the user so that he may remove the key for use. Thesomewhat cumbersome process of reading on a computer screen the row andcolumn within a Key Track drawer of the requested key and manuallylocating that position within the drawer to find the key is eliminated,as is the likelihood of human error associated selecting the proper tagand key. The user simply requests a particular key and removes thelighted key tag from the drawer. In the preferred embodiment, the tagstays lighted for a few seconds after it is removed as a confirmationthat the correct key tag has been drawn from the system.

As mentioned above, a light guide such as that of FIG. 9 directs lightefficiently along its length with very little loss of light through itsside faces. This has the potential of causing a problem if a Key Tracksystem user happens to be viewing tags in the system from a perspectivein which the edges of the tags are not visible but the side faces are.In this situation, the user might not easily discern a lighted tag fromunlighted tags. To address this problem, a discontinuity 221 is formedin one or both faces of the upper portion of the key tag 201. In theillustrated embodiment, the discontinuity 221 takes the form of one ormore grooves scored in the face. However, it could take other forms suchas, for instance, bumps, depressions, raised areas, roughened areas,etc. formed on the face such that the term “discontinuity” as usedherein includes any suitable configuration of features that may beformed on the face. In any event, the discontinuity 211, by breaking thesmooth surface of the face, diverts some of the light propagating up thelight guide out the side face thereof. As a result, a lighted tag is nowclearly visible either from an edge perspective or from a faceperspective and can be identified easily by a user regardless of hisviewing angle.

FIGS. 10 and 11 illustrate yet another embodiment of a lighted key tagaccording to the present invention. In many respects, the key tag ofthis embodiment is similar to that of the previously discussedembodiment such that further detailed discussion of these aspects of thetag is not required here. The main difference between the twoembodiments is that the embodiment of FIGS. 10 and 11 does not make useof a light guide to light the tag but rather simply positions LED'sthemselves at selected locations on the tag so that they are visible toa user. Referring in more detail to FIGS. 10 and 11, a key tag 230comprises a printed circuit board (PCB) 226 and a housing 236 that isconfigured to be slipped over, receive, and house the upper portion ofthe PCB. When so joined (FIG. 11) the key tag resembles in many respectsa standard key tag disclosed in the incorporated references in that ithas a depending tongue configured to be received in a slot of a KeyTrack system and an upper portion, formed by the housing, that projectsupwardly from the slot and to which a key or keys are securely affixed.The PCB 226 has a lower portion 227, which forms the tongue of theassembled tag, and an upper portion 228 that is disposed within thehousing of the assembled tag. The lower portion 227 is provided with araised conductive pad 229 on one side and a flush conductive pad (notvisible) on the opposite side. As with the prior embodiment, these padsinsure that the tag is inserted in a Key Track slot in the correctorientation and connect with connectors of the system for communicatingwith a system controller. The upper portion 228 of the PCB carries thecomponents of an electronic circuit 231, which includes a battery 232, afirst LED 233, and a second surface mount LED 234. The conductive padson the tongue are connected to the circuit 231 and, as with previouslydiscussed embodiments, the circuit is configured to activate the LEDswhen the tag is in a Key Track system slot and its key is requested by auser of the system. The PCB is also formed with a key attachment hole235 adjacent its top edge and a locking or retainer slot 230 adjacentits right edge, for purposes detailed below.

The housing 236 has an internal compartment terminating in a slot 240with the slot and compartment being configured to receive the upperportion 228 of the PCB. The housing is sized such that when it is slidover the PCB, the electronic circuit 231 is enclosed within andprotected by the housing with only the lower portion 227 and itsconductive pads depending from the housing for insertion into a slot ofa Key Track system (FIG. 11). The housing is formed with an internalretainer bolt 241 that is sized and positioned in the interiorcompartment of the housing such that when the housing is slid onto thePCB, the retainer bolt 241 snaps into the retainer slot 230 to lock thehousing and PCB securely together. Many other methods of locking the twocomponents together are also possible and all should be considered to bewithin the scope of the invention. A hinged flap 300 may be incorporatedinto the slot if desired to close against the PCB after the electroniccomponents are completely within the housing to protect the interior ofthe housing from dust and tampering.

The housing 236 is further formed with a key attachment hole 237 thataligns with the hole 235 in the PCB when the two components areassembled so that a key or keys can be securely attached to the tag witha rivet or other fastener extending through the aligned holes. A lightopening 238, which may or may not include a integral lens, is formed inthe top edge of the housing 236 and a similar light opening 239 isformed in the side face of the housing. The light openings 238 and 239are positioned to align with the LEDs 233 and 234 respectively when thehousing and PCB are joined so that light emitted from the LED's can beseen through the holes. Thus, the LED's, when lit, project their lightupwardly from the top edge of the key tag and sidewise from the sideface of the tag. As with the prior embodiment, when a user requests akey associated with a key tag stored in a Key Track system, the circuit231 of that key tag lights the LEDs 233 and 234, which, in turn,identify the requested key to the user regardless of the viewingperspective of the user.

FIG. 12 is an electronic schematic illustrating a preferred embodimentof the electronic circuits 211 and 231 of the key tags in FIGS. 10 and11 respectively. The circuit is virtually the same as the circuit ofFIG. 7 with the battery alternative implemented rather than drawingpower from the Key Track system through a third conductive pad on thetongue of the key tag. In this way, the lighted tags of this inventionfunction with existing two wire Key Track systems such as thosedisclosed in the incorporated patents. Referring in more detail to FIG.12, the circuit, as is the circuit in FIG. 7, is based around anaddressable switch chip that stores a unique identification code andthat can be addressed by that code to cause the chip to set its I/O portor ports high or low or to toggle them depending upon the particularchip chosen. In the preferred embodiment of FIG. 12, the addressableswitch chip is a DS2405 addressable switch available from DallasSemiconductor that sets its I/O port low (i.e. connects it to the groundpin) when the chip is addressed. However, this particular chip is not alimitation of the invention and other addressable switches may besubstituted. Indeed, any chip, whether or not it is formally known as an“addressable switch,” that can be configured to respond in a mannerusable to light an LED when addressed by a controller is contemplated tobe within the scope of this invention and is included within the meaningof the term “addressable switch” as used herein.

The addressable switch in the circuit of FIG. 12 has a data pin, aground pin, and a input/output or PI/O pin. The data pin is electricallyconnected to the conductive pad of a key tag used for addressing theswitch and the ground pin is connected to the ground or data returnconductive pad. The pads, in turn, connect the addressable switch to thecomputer controller through electrical contacts when a key tag isinserted into a slot of a Key Track system. A zener diode D1 may beconnected between the data and ground pins of the addressable switch ifdesired to protect the switch against voltage spikes and electrostaticdischarges. The I/O pin of the addressable switch is connected to thebase of transistor Q1, which is configured as a switch. The transistorQ1 may be a BSS84 P-Channel Enhancement Mode Vertical DMOS FET or anyother suitable transistor capable of switching sufficient current tooperate an LED. A current limiting resistor R3 is connected in serieswith the I/O addressable switch to limit current through the addressableswitch chip and to provide a short protective time buffer. Thetransistor Q1 is configured to switch on when the I/O pin of theaddressable switch is set low and pulls the base of the transistor lowas a result of the addressable switch being addressed with its uniqueidentification code. One or more LED's, depending upon the key tagembodiment, is connected in series with the transistor Q1 through acurrent limiting resistor R1. Power for lighting the LED is provided bya battery, which, in the preferred embodiment, is a 3V Lithium Ionbattery for long reliable life. It will thus be seen that when theaddressable switch in a key tag is addressed by a Key Track controllerwith the identification code of the switch, the I/O pin of the switch ispulled low, which causes transistor Q1 to switch on thereby lighting theLED.

It has been noted during development of lighted key tags that the LEDshuts off when the key tag is removed from its slot because the I/O portof the addressable switch resets to a floating state and is pulled highimmediately by the battery. However, it is desirable for the key tag tostay lighted for a short period after it is removed from its slot as aconfirmation to the user that the correct tag has indeed been removedfrom the Key Track system. In order to address this need, the circuit ofFIG. 12 includes a delay function provided by capacitor C1 and resistorR2. Briefly, this delay circuit functions as follows. The transistor Q1is on (conducting) when its base is low. Accordingly, when theaddressable switch is addressed and sets its I/O pin low in response,the base of the transistor is pulled low through resistor R3 and thetransistor turns on to light the LED. When the key tag is removed fromits slot, the disconnection immediately causes the I/O pin of theaddressable switch to float (i.e. it is no longer connected to theground pin). This normally would cause the transistor to turn offimmediately since its base would be pulled high instantly by thepositive terminal of the battery. However, with the delay function inplace, the capacitor C1 begins to charge slowly through resistor R2according to a time constant determined by the values of resistance andcapacitance (about 2-3 seconds for example). When the capacitor chargesto a voltage above the turn-on threshold of the transistor, thetransistor turns off and the LED is extinguished. Accordingly, when thekey tag is removed from its slot, the tag remains lighted for a shortperiod of time (2-3 seconds) to confirm to the user that he has pulledthe correct tag. The delay circuit also addresses the tendency of theLEDs to flash or blink intermittently when the key tags are in theirslots due to unexpected data matrix events such as shorts.

The invention has been described herein in terms of preferredembodiments and methodologies. It will be clear to those of skill in theart, however, that various additions, deletions, and modifications mightwell be made to the illustrated embodiments within the scope of theinvention. For example, the tag lighting technique of FIG. 9 wherein aportion of the tag forms a clear light guide also is applicable to keyboxes such as the key box illustrated in FIG. 6. In such a key box, oneside of the box or the entire box might be fabricated of a transparentplastic or other material that forms a light guide for directing lightupwardly to the exposed top of the box. While not specifically discussedabove, it has also been found advantageous to include a simple flashingcircuit to cause the LEDs of key tags to flash rather than just turningon when the tags are addressed. Also, while plastics are consideredideal materials for forming many of the components of the lighted tagsand PCB material ideal for carrying electronic components, thesematerials are not limiting to the invention and any suitable materialmay be selected for any of the components of the tags, all within thescope of the invention. These and numerous other additions, deletions,and modifications might well be made to the preferred embodimentsdisclosed herein without department from the spirit and scope of theinvention as set forth in the claims.

1. In a key tracking system wherein a plurality of keys are eachattached to a trackable object and are removably storable in a storageunit, the keys being individually requestable by a user via a computercontroller coupled to said storage unit, the improvement comprising anLED on each trackable object and an electronic circuit in each trackableobject coupled to said LED, each of said electronic circuits beingadapted to light its LED when a key attached to the trackable object isrequested by the user to identify to the user the location of therequested key within the storage unit.
 2. The improvement of claim 1 andwherein said storage unit has a plurality of slots for receivingtrackable objects stored in said storage unit and wherein each of saidtrackable objects comprises a key tag having a lower portion configuredto be received in a selected slot when said key tag is stored in saidstorage unit.
 3. The improvement of claim 2 and wherein each key has anupper portion that projects upwardly from a slot in which said key tagis received and to which keys associated with said key tag are affixedand wherein said LED, when activated, projects light at least upwardlyfrom said upper portion of said key tag.
 4. The improvement of claim 3and wherein said LED is disposed at a top edge of said upper portion ofsaid key tag and projects light upwardly therefrom such that the lightedLED is visible to a user from the top of said key tag.
 5. Theimprovement of claim 4 and further comprising a second LED disposed on aside of said upper portion of said key tag and coupled to electroniccircuit for projecting light sidewardly therefrom when activated suchthat the lighted second LED is visible to a user from the side of saidkey tag.
 6. The improvement of claim 3 and wherein said upper portion ofsaid key includes an upwardly extending light guide having a bottom endand a top end terminating at a top edge of said upper portion, said LEDpositioned to project light into said bottom end of said light pipe. 7.The improvement of claim 6 and wherein said upper portion of said keytag is made of an at least partially transparent material that formssaid light guide, the light from said LED propagating upwardly throughsaid upper portion and projecting from edges of said upper portion whensaid LED is activated.
 8. The improvement of claim 7 and furthercomprising a discontinuity formed in at least one side of said upperportion, said discontinuity diverting a portion of the light from saidLED sidewise of said upper portion.
 9. A key tag for use in a Key Tracksystem, said key tag comprising: a lower portion bearing contacts forcoupling with the Key Track system; a mid portion housing an electroniccircuit that includes memory storing an identification code uniquelyidentifying said key tag and a key attached thereto, said electroniccircuit being addressable by said Key Track system; an upper portion towhich a key associated with said key tag may be affixed; an LED coupledto said electronic circuit, said electronic circuit lighting said LEDwhen addressed by said Key Track system; said LED, when lighted,projecting light at least upwardly from said upper portion of said keytag to identify said key tag visually to a user of said Key Tracksystem.
 10. A key tag as claimed in claim 9 and wherein said LED islocated at a top edge of said upper portion.
 11. A key tag as claimed inclaim 10 and further comprising a second LED coupled to said electroniccircuit, said second LED being located on a side of said upper portion.12. A key tag as claimed in claim 9 and wherein said electronic circuitmaintains said LED lighted for a predetermined period of time afterbeing addressed by said Key Track system.
 13. A key tag as claimed inclaim 9 and wherein said upper portion of said key tag forms a lightguide, said LED, when lit, projecting light upwardly through said lightguide to be emitted from exposed edges of said upper portion.
 14. A keytag as claimed in claim 13 and wherein said LED is located in said midportion of said key tag and is located and oriented to project lightinto said light guide formed by said upper portion when lighted.
 15. Akey tag as claimed in claim 13 and further comprising at least onefeature formed on a side of said upper portion for diverting some ofsaid light from said light guide sidewise of said upper portion of saidkey tag.
 16. A key tag as claimed in claim 15 and wherein said featureincludes grooves.